Originally Posted by Inverse
Anytime I've jumped to a new "DX" level, all I do is enable features that further slow down the card anyway. When DX10 came out, I got an 8800 series card and more often than not found myself disabling the "choose this to remove 10-15 frames per second" feature. There isn't anything in DX11 I'd consider really motivating for a new card. Not yet anyway, maybe after Battlefield 3, but are there any current gen examples?
In all honesty, DX11 is mostly an optimized DX10 that helps to alleviate some of the performance overhead while offering the same visual effects. Most recent DX10 cards, including your GTX 295, can readily support a number of DX11 features due to the fact that it really isn't a complete departure from the previous generation. In fact, the main feature that has been used in a handful of games is tessellation, which unless if you were directly comparing a non-tessellated texture versus one that is tessellated side-by-side, you may be hard pressed to notice a difference.
There really aren't any shining examples of game altering usages of tessellation, but Lost Planet 2, Metro 2033, and Crysis 2 (with DX11 patches) are ones that do stick out that boast making use of this feature.
Here's an article that may interest you:
In my opinion, the only convincing reason why you should consider upgrading to a current generation card from a GTX 295, would be for better performance in games that you play today regardless of what DX revision it may or may not support. Newer cards, while they do support higher DX versions, are great just for the pure fact that they offer better performance in older DX games. Other reasons that may or may not influence you include better folding performance, higher scores in benchmarking, cooler/quieter running card(s), the ability to play games smoothly in 3D, and better performance in Surround.
To upgrade just for a DX revision, especially DX11 (at this very moment), is not going to give you the mind blowing experience that it is made out to be.